title: Risk factors for increased antimicrobial resistance: a retrospective analysis of 309 acute cholangitis episodes.
abstract: OBJECTIVE
  To assess the risk factors for increased antimicrobial resistance among Enterobacteriaceae representing the most common biliary pathogens.
  
  
  METHODS
  A retrospective analysis was conducted of 276 patients with acute cholangitis treated at a German tertiary centre between April 1996 and May 2009. The resistance patterns among Enterobacteriaceae isolated from blood/bile cultures were compared and related to age, sex, the genesis of the cholangitis and the type and number of previous interventional procedures [percutaneous transhepatic cholangiography (PTC)/endoscopic retrograde cholangiography (ERC)]. Univariate and multivariate generalized estimation equation models were used to compute ORs with corresponding 95% CIs for the binomial outcomes.
  
  
  RESULTS
  According to the univariate analysis, patients undergoing stent therapy had a smaller proportion of Enterobacteriaceae with susceptibility to quinolones (ofloxacin/ciprofloxacin) (184/239 versus 205/221; P < 0.001) and to ceftriaxone (208/239 versus 209/222; P = 0.014). Logistic regression analysis revealed that the odds for acquiring ceftriaxone-resistant Enterobacteriaceae were 4-fold higher than in patients who had not undergone stent therapy (P = 0.039). Furthermore, an increased number of interventional procedures (PTC/ERC) was associated with lower susceptibility. The odds for susceptibility to ampicillin, ampicillin/sulbactam, ceftriaxone, quinolones and co-trimoxazole decreased by 2%, 2%, 4%, 6% and 3%, respectively, per interventional procedure. Age, sex and type of interventional procedure displayed no significant relationship to the development of antimicrobial resistance.
  
  
  CONCLUSIONS
  Stent therapy was found to be a risk factor for increased antimicrobial resistance in patients with acute cholangitis, particularly those who had undergone numerous interventional procedures prior to the onset of the cholangitis.
authors.affiliation: Institute of Medical Microbiology, Immunology and Hygiene, Technische Universität München, München, Germany.
authors.forename: Jochen
authors.initials: J
authors.lastname: Schneider
authors.forename: Pierre
authors.initials: P
authors.lastname: De Waha
authors.forename: Alexander
authors.initials: A
authors.lastname: Hapfelmeier
authors.forename: Susanne
authors.initials: S
authors.lastname: Feihl
authors.forename: Franziska
authors.initials: F
authors.lastname: Römmler
authors.forename: Christoph
authors.initials: C
authors.lastname: Schlag
authors.forename: Hana
authors.initials: H
authors.lastname: Algül
authors.forename: Roland M
authors.initials: RM
authors.lastname: Schmid
authors.forename: Nina
authors.initials: N
authors.lastname: Wantia
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Huber
authors.forename: Andreas
authors.initials: A
authors.lastname: Weber
mesh_terms: D000208:Acute Disease; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000900:Anti-Bacterial Agents / Q000494:pharmacology / Q000627:therapeutic use*; D002761:Cholangitis / Q000175:diagnosis / Q000188:drug therapy* / Q000382:microbiology*; D024901:Drug Resistance, Multiple, Bacterial / Q000187:drug effects* / Q000502:physiology; D004724:Endoscopy / Q000009:adverse effects; D006801:Humans; D008875:Middle Aged; D012189:Retrospective Studies; D012307:Risk Factors; D015607:Stents / Q000009:adverse effects
chemical_list: D000900:Anti-Bacterial Agents
keywords: Enterobacteriaceae; bacterial infections; gastrointestinal tract microbiology